1. Field of the Invention
The present invention relates to a dynamic damper which is to be fitted onto an outer peripheral face of a rotary shaft such as a drive shaft of a vehicle, and which damps a vibration input produced on the rotary shaft.
2. Background Art
Conventionally, a dynamic damper of this kind comprises, for example, a tubular metallic mass, and a tubular rubber elastic member which extends from the inner peripheral face of the metallic mass toward the axial center. The rubber elastic member has an attachment tube which is placed on the side of the axial center, and an arm which couples the attachment tube with the metallic mass. The attachment tube is fitted by pressing onto an outer peripheral face of a rotary shaft such as a drive shaft in which vibrations are to be damped, whereby the metallic mass is elastically held onto the drive shaft. In the dynamic damper, in response to a harmful vibration input such as bending or torsional vibrations produced by rotation of the drive shaft, the rubber elastic member is compressively deformed by a resonance effect due to vibrations of the metallic mass, and the vibration input is absorbed and damped by the compression deformation. In the dynamic damper, in order to enhance the strength of attachment of the attachment tube to the drive shaft, a ring-like fastening band is fastened while being wound around a part of the attachment tube. According to the configuration, the dynamic damper is firmly positioned and fixed to the drive shaft, and axial movement of the dynamic damper due to vibrations of the drive shaft is suppressed, thereby enabling the dynamic damper to exhibit stable vibration absorption characteristics.